A/C goes warm after engaging recirculate.

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May 4, 2008
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This is in our 2015 Impala, had a couple recent threads on this vehicle but I believe it's an isolated incident. I listed the 2 threads if anyone wants to read up.






Quick history, AC would take a long time to engage when ambient was about 80 deg or more, then get warm as the vehicle slowed. Condenser was banged up a little, many folded fins, slow leak at high side Schrader, slightly larger leak at low side Schrader. Residue on compressor under line manifold, car has 140K miles.

Had the system evacuated and recharged at a shop, acted the same about an hour after the charge...but when blowing cold it would get down to about 42 deg at the vents.

So I replaced the condenser, compressor control solenoid, O rings at manifold, O ring at suction line junction before the compressor, and both schrader valves.

Pulled a good vacuum for 2 hours, and held the vacuum for 15 min. I recharged with 1.5 lbs of R134A, and it has been working fine for about 3 days now.

Now the issue is, we haven't used recirc yet, it gets down to 40-42 deg without it as ambient is around 65-70 deg. After driving for 30 min, we came to a stop, and turned on recirc....after about 15 sec, you could feel it get warm and humid in the cabin, and the temps went from 42 deg to 60 deg. Drove around and it slowly started to come down but not much, turn off recirc at the temp at the vents dropped to 42.

Parked car and did another drive a couple hours later, drove around with recirc off, temp set to LO, and vents were at 41-42 deg for 20 min, came to a stop and temps stayed at 42. Waited a couple min and turned on recirc, again in 10-15 sec, it got humid, and temps went to just over 60 deg at the vents. We let it idle and turned off recirc, after a min, temps dropped to 42 deg again.

Is this a mode door issue, or a problem with the control module? The clutch on the compressor I believe always is engaged with te AC on, and when it got warm it was still engaged.

At first I thought there was another leak, but it works perfect with the recirc turned off.
 
This is in our 2015 Impala, had a couple recent threads on this vehicle but I believe it's an isolated incident. I listed the 2 threads if anyone wants to read up.
....
Is this a mode door issue, or a problem with the control module? The clutch on the compressor I believe always is engaged with te AC on, and when it got warm it was still engaged.

At first I thought there was another leak, but it works perfect with the recirc turned off.
If the compressor clutch is engaged when you put it on recirculate and it gets warm, the issue is with the mode door/blend door, not with the refrigeration system. Not familiar with the specific HVAC controls on a 2015 Impala, but I'd focus on the blend door temperature actuator(s) before diving into the control panel & module/BCM.
 
Blend door temp control is probably isolating the airflow around the evaporator and blowing warm cabin air around without cooling it. As @Nukeman7 stated, check actuators/motors for movement/limits.
 
I'll look into the actuators, also I wanted to mention, both temp control knobs work fine with controlling cabin temps....no large temp swings. Also the modes work as they should, face, feet, both, and defrost.

The only time it gets warm is with recirc....and that's with cold cabin air.

I also don't know if 2 or more doors move with recirc, that I will look into.
 
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